The court heard Edwin Maheno and the couple were living at the property where he had grown up raised by his grandmother. When she died in 2009, the property was bequeathed to Ivan Maheno.
On May 19 Maheno overheard a conversation between the victims regarding his inability to stick to domestic chores and accusations he had left coffee granules in a sugar bowl.
Edwin Maheno was so incensed by the insults he loaded his .22 rifle, pointed it at Ivan Maheno and shot him in the head, despite profuse apologies from the victim, followed by a shot to the right cheek.
"Ivan had crawled out of the bedroom into the hallway. He was still alive and was trying to push himself off the floor. He begged you for his life. You shot him again in the head,'' the judge said.
Carmen Maheno ran to investigate, and struggled with the defendant, who punched her in the head, struck her in the abdomen with the rifle barrel then in the head with the butt as she crouched on the floor.
There was a second struggle as the defendant tried to reload the rifle.
Carmen Maheno ran towards a neighbouring farm fence in a desperate bid to escape.
"She climbed over the wire fence and kept running. You stayed your side of the fence, raised the rifle, took aim and shot her once in the back of the head. She fell to the ground. You could see she was still breathing. You shot her a second time in the buttocks.''
She died 12 hours later in Whangarei Hospital.
Edwin Maheno then drove away from the house, with the rifle, telling an uncle he met at the bottom of the driveway that he had fatally shot the victims.
He eventually turned himself into Kaitaia police.
Maheno told police he became angry at the way he had been treated by the victims since they moved into the house after inheriting it, and felt they were not respecting the family homestead. He had killed them so the property would go to the other siblings.
At an earlier hearing, his lawyer Ken Bailey said his client had never denied his actions, and acknowledged and thanked the court for the opportunity to enter pleas before his people.
"It was important to him to acknowledge his guilt before his whanau and this community,'' Mr Bailey said, adding that Maheno's actions were the result of a long-standing , "fundamental'' feeling he had that the wairua that held his world together had been badly interfered with.
He fully acknowledged the "wrongness'' of his actions, however.
But the judge today dismissed suggestions Maheno was remorseful for the killings.
"You still seem to retain this rather perverse idea that you acted for the benefit of your family and that in some way justifies what you have done. That is apparent from the probation officer's notes that while you say you regret what you have done to Ivan, you do not regret what you did in relation to Carmen.''
